Mr. Smith described himself as an executive director and head of Goldman’s U.S. equity derivatives business in Europe, the Middle East and Africa.

A person familiar with the matter said Mr. Smith’s role is actually vice president, a relatively junior position held by thousands of Goldman employees around the world. And Mr. Smith is the only employee in the derivatives business that he heads, this person said.

Some at the firm think things might get ugly.

"They're going to want to destroy this guy's credibility. Watch for more leaks about him," said one person at the firm.

Another agreed.

"He's pi**ed off the wrong guys. And they're not going to take this lying down," the person said.